Method for making punch head of paper punch

ABSTRACT

A method for making punch heads includes a step of pulling a cylindrical metal material wrapped around a mandrel; a step of cutting the cylindrical metal material into sections; a step of inserting the sections into concavity of a mold set and punching a recess in a first end of each section by a first tool; a step of punching the recess into V-shaped recess and including a punching edge by a second tool; a step of pushing the sections out from the mold set by a pushing rod; and a step of obtaining a punch head.

FIELD OF THE INVENTION

The present invention relates to a method for making punch heads by an efficient way.

BACKGROUND OF THE INVENTION

A conventional method for making punch heads is disclosed in FIGS. 1 and 2, and generally includes the following steps:

Step 1: preparing a long tube 11;

Step 2: cutting the long tube 11 in sections at desired length;

Step 3: making a groove 14 or a hole 15 in each section and a rounded edge 13 defined in a first end 12 of each section;

Step 4: making a punching edge 16 in a second of each section by a tool 20;

Step 5: proceeding a heat treatment to each section;

Step 6: surface grinding for each section;

Step 7: anti-rust treatment; and

Step 8: obtaining a final punch head 10.

It is noted that the manufacturers have to install the long tube 11 frequently and each long tube 11 can only be made into limited number of sections. The sections are made to have the punching edge 16 one by one and this is a time-consuming job. Besides, the tools 20 are worn out quickly and the debris of the long tubes and sections is harmful to the manufacturers.

The present invention intends to provide an easy and efficient way to make the punch heads which can be made within a short period of time.

SUMMARY OF THE INVENTION

The present invention relates to a method for making punch heads and the method comprises:

step 1: pulling cylindrical metal material wrapped around a mandrel;

step 2: cutting the cylindrical metal material into sections;

step 3: inserting the sections into concavity of a mold set and punching a recess in a first end of each section by a first tool;

step 4: punching the recess into V-shaped recess and including a punching edge by a second tool; and

step 5: pushing the sections out from the mold set by a pushing rod.

The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the steps of a conventional method for making a punch head;

FIG. 2 shows the diagrams of the results of the steps in FIG. 1;

FIG. 3 shows the steps of the method of the present invention for making a punch head;

FIG. 4 shows the diagrams of the results of the steps in FIG. 3;

FIG. 5 is a perspective view to show a first type of the punch head made by the method of the present invention, and

FIG. 6 is a perspective view to show a second type of the punch head made by the method of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 3 to 4, the method of the present invention for making punch heads comprises the following steps:

step 1: pulling an end of a roll of solid strip of cylindrical metal material 30 wrapped around a mandrel 300 and two guide wheels 40 clamping forward the end of the cylindrical metal material 30;

step 2: cutting the cylindrical metal material 30 into sections 31;

step 3: inserting the sections 31 into concavity 51 of a mold set 50 and punching a recess 311 in a first end of each section 31 by a first tool 52, a second end of each section 31 being pressed to form a rounded edge 312;

step 4: punching the recess 311 into a sharp V-shaped recess 313 and including a punching edge by a second tool 53;

step 5: pushing the sections 31 out from the mold set 50 by a pushing rod 54;

step 6: making a groove 314 or a hole 315 in the section 31 according to practical needs as shown in FIGS. 5 and 6;

step 7: proceeding a heat treatment to each section 31;

step 8: surface grinding for each section 31;

step 9: applying anti-rust treatment to each section 31; and

step 10: obtaining a final punch head 60.

In step 3, the concavity 51 includes a narrow section which forms an inclined shoulder 511 such that when the first end of each section 31 is punched into a recess 311, the second end of each section 31 is pressed onto the inclined shoulder 511 to form the rounded edge 312. It is noted that the cylindrical metal material 30 occupies less space than the long tube in the conventional method so that more sections 31 can be made continuously within a short period of time. The mold set 50 can be rotated to be treated by different stations where different tools 52, 53 are located, by this way, the manufacturing time can be saved. The solid punch head 60 has better structural strength and the V-shaped punching edge efficiently penetrates document.

While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention. 

1. A method for making punch heads, comprising: step 1: pulling cylindrical metal material wrapped around a mandrel; step 2: cutting the cylindrical metal material into sections; step 3: inserting the sections into concavity of a mold set and punching a recess in a first end of each section by a first tool; step 4: punching the recess into a V-shaped recess and including a punching edge by a second tool; step 5: pushing the sections out from the mold set by a pushing rod; step 6: obtaining a punch head.
 2. The method as claimed in claim 1 further comprising two guide wheels and the cylindrical metal material being transported by rotation of the two guide wheels.
 3. The method as claimed in claim 1, wherein a second end of each section is pressed to form a rounded edge in step
 3. 4. The method as claimed in claim 1, wherein the cylindrical metal material is a solid cylindrical strip.
 5. The method as claimed in claim 1, wherein the concavity includes a narrow section which forms an inclined shoulder and the second end of each section is pressed onto the inclined shoulder to form the rounded edge.
 6. The method as claimed in claim 1 further comprising a step of making a groove or a hole in the section between steps 5 and
 6. 